The P2P communication application is widely applied to the network communication in today's Internet for sharing data, for example involving file sharing, multimedia streaming, and resource dispatching. In contrast to the traditional client-server communication mode, where only servers supply (send) and clients consume (receive), a P2P communication enables each participant (hereinafter referred to as “peer node(s)”) of the communication communicate over a distributed network architecture. Peer nodes in a P2P network are equally privileged, so that the communication can be directly made among one or more peer nodes, without any need for central coordination by servers.
In the wireless communication environment, a P2P communication mode can also be used for information collecting and sharing among wireless devices, such as mobile phones, tablet computers, digital media players, or other devices capable of wireless communication. The P2P communication application implemented in the wireless communication environment can be called a wireless P2P communication application. The wireless communication network in a P2P communication mode can be called a wireless P2P communication network. This wireless P2P communication network can be implemented with an infrastructure supports (such as cellular network), or without any infrastructure support (such as ad hoc network). The wireless P2P communication network can provide short range, high data rate communication between wireless devices. After a wireless P2P communication link is setup, signals and data can be transferred between the wireless devices, without traversing through an access node (such as a base station) or centrally managed network.
As the rapid development of wireless communication technology, radio interfaces of more and more wireless communication technologies, e.g. Wi-Fi (IEEE 802.11b and 802.11g), GSM (Global System of Mobile communication), Bluetooth™ (including Bluetooth™ Low Energy (BT LE)), or ZigBee (IEEE 802.15.4, IEEE 802.15.4a), etc., can be equipped in wireless devices. Meanwhile, various techniques have been or are being incorporated into Personal Area Networks (PAN) to support Internet Protocol (IP) over various radio interfaces, such as 6LowPAN (IPv6 over Low power Wireless Personal Area Networks) for ZigBee, BNEP (Bluetooth Network Encapsulation Protocol) for Bluetooth™, and the ongoing IP over BT LE standardization process. These, to a large extend, pave the way for an interoperable design in realizing a wireless P2P communication application with various radio interfaces in wireless devices.
In the wireless P2P communication application, the data access patterns are opportunistic, since data is only exchangeable when there are peer nodes available to be communicated and when some of them having same interests. To meet the demand of a P2P communication application in wireless communication environment, radio interfaces in the wireless device are required being open all the time to execute constantly resource discovery operations for a P2P communication, such as neighbor discovery, data query, index exchange, etc. This resource discovery process is time/energy consuming, causing excessive energy consumption to the wireless devices. Energy consumption is a significant problem for wireless devices. Especially for those wireless devices powered by batteries, the excessive energy consumption in a P2P communication will largely shorten their working cycles.
A number of power-saving techniques have been proposed to reduce power consumption in wireless P2P communication. However, current techniques have not sufficiently addressed the issue of power consumption while provide high efficiency of data delivery. Traditional wireless P2P communication systems partially solve this problem by introducing low-energy radio for wireless P2P communication. For example, “Bluetorrent: Cooperative content sharing for bluetooth users” Percom 2007, March 2007, by Sewook Jung, etc. proposed a solution of building a wireless P2P file sharing application totally upon low-power and short-range Bluetooth networks that are always-on. This solution, though mitigates the energy consumption, has an obvious limit in transmission bandwidth of 1 Mbps, which is far below users' expectation in P2P applications.
Another power-saving technique is using multiple radio interfaces in a mobile device to concurrently communicate on different channels for heterogeneous P2P communication. For example, Ze Zhao, etc. mentioned this kind of wireless P2P communication in “A multi-radio wireless P2P network testbed” (in Proceedings of the 4th ACM international workshop on Experimental evaluation and characterization (WINTECH '09). ACM, New York, N.Y., USA, Page 93-94). However, this kind of multi-radio wireless P2P communication system now only supports concurrent transmission on multiple radio interfaces, but does not involve specific design for how and when to use these multiple radio interfaces for distributing the traffic of a P2P communication application.
Some wireless communication mechanism for a mobile device equipped with multiple radio interfaces have been proposed, wherein different radio interfaces are adopted for transport traffic according to bit rates of the traffic. For example, Tao Jin, etc. proposed to adopt Wi-Fi interface for high bit rates and adopt Zigbee for lower bit rates in “WiZi-Cloud: Application-transparent Dual ZigBee-Wi-Fi Radios for Low Power Internet Access”, in IEEE Infocom, Shanghai, China, April, 2011. Bluetooth SIG proposed to adopt UWB interface for high bit rates and adopt Bluetooth interface for lower bit rates in “Version 3.0+HS of the Bluetooth Core Specification,” Apr. 21, 2009. This communication mechanism may serves as a low-power transmission method and works well in static scenarios where wireless access is stable for different radio interfaces. However, this communication mechanism may not work well for the wireless P2P communication application. In the wireless P2P communication application, the peer nodes (i.e. wireless devices) moves dynamically, and the communication link in a P2P communication mode through the two radio interfaces will be interrupted constantly. Then, the high-energy radio interface may be inappropriately used for low bit rate traffic, and vice versa, the low-energy radio being inappropriately used for high bit rate traffic. For example, according to the solution of Tao Jin, when the communication link through the Zigbee radio interface is interrupted, the traffic of a P2P communication application will be handover to the Wi-Fi radio interface, causing much high energy consumption; when the communication link through the Wi-Fi radio interface is interrupted, the traffic of a P2P communication application will be handover to the Zigbee radio interface, causing inefficient data transfer. Additionally, in the solution of Tao Jin, WiZi is built in centralized networks where networking infrastructures such as Access Points (APs) are necessary; and it is not applicable in ad-hoc networks where no networking infrastructure exists. However, in the P2P communication, a networking infrastructure is not limited within the scope of centralized networks, but also comprising ad-hoc networks where no networking infrastructure exists. Besides, as frequent resource discovery operation, such as neighbor discovery, data query, index exchange, etc, is a necessity for P2P communication application, using traditional Bluetooth radio interface for continuous peer discovery mode will cause much high energy consumption.
Thus, it would be advancement in the art to provide methods and apparatus that allow for a wireless P2P communication that can overcome the above limitations and disadvantages.